A high-throughput approach measures cell type-specific telomere lengths in fixed archival tissues from patient cohorts for research on prognosis

Telomeres, the repetitive DNA elements at chromosome ends, are pivotal for maintenance of genome integrity. Previous studies from our group and others have highlighted the translational potential of tissue-based telomere length measurements to address the clinical challenge of improving diagnosis, individualized risk stratification, and accurate prognostication of different diseases. Here, we describe a high-throughput method that quantitates cell type-specific telomere lengths at a single cell level in archival tissues from patient cohorts for research on prognosis. This approach is based on telomere-specific fluorescence in situ hybridization (FISH) combined with multiplex immunostaining for cell type-specific antibodies, followed by semi-automated slide scanning and multi-channel acquisition of fluorescent images using the TissueFAXS Plus microscopy workstation and TissueQuest software (TissueGnostics). Here, we demonstrate that this method is sufficiently robust and reproducible to detect biologically significant differences in telomere lengths in archived tissues either on whole slides or sampled across tissue microarrays, which is essential when assessing prognosis in large patient cohorts.